Page 19 - Modern Control Systems

Preface XV
direct feedback, you can check your answers with the answer key provided at the
conclusion of the end-of-chapter problems.

PEDAGOGY

The book is organized around the concepts of control system theory as they have
been developed in the frequency and time domains. An attempt has been made to
make the selection of topics, as well as the systems discussed in the examples and
problems, modern in the best sense. Therefore, this book includes discussions on
robust control systems and system sensitivity, state variable models, controllability
and observability, computer control systems, internal model control, robust PID con-
trollers, and computer-aided design and analysis, to name a few. However, the classi-
cal topics of control theory that have proved to be so very useful in practice have
been retained and expanded.

Building Basic Principles: From Classical to Modern. Our goal is to present a clear
exposition of the basic principles of frequency- and time-domain design techniques.
The classical methods of control engineering are thoroughly covered: Laplace trans-
forms and transfer functions; root locus design; Routh-Hurwitz stability analysis;
frequency response methods, including Bode, Nyquist, and Nichols; steady-state
error for standard test signals; second-order system approximations; and phase and
gain margin and bandwidth. In addition, coverage of the state variable method is
significant. Fundamental notions of controllability and observability for state vari-
able models are discussed. Full state feedback design with Ackermann's formula for
pole placement is presented, along with a discussion on the limitations of state vari-
able feedback. Observers are introduced as a means to provide state estimates when
the complete state is not measured.
Upon this strong foundation of basic principles, the book provides many oppor-
tunities to explore topics beyond the traditional. Advances in robust control theory
are introduced in Chapter 12. The implementation of digital computer control sys-
tems is discussed in Chapter 13. Each chapter (but the first) introduces the student
to the notion of computer-aided design and analysis. The book concludes with an
extensive references section, divided by chapter, to guide the student to further
sources of information on control engineering.

Progressive Development of Problem-Solving Skills. Reading the chapters, attending
lectures and taking notes, and working through the illustrated examples are all part of
the learning process. But the real test comes at the end of the chapter with the prob-
lems. The book takes the issue of problem solving seriously. In each chapter, there are
five problem types:
• Exercises
• Problems
Q Advanced Problems
Q Design Problems
Q Computer Problems